Intermittently-variable drive mechanism



D 8, 1953 M. F. CAMPBELL INTERMITTENTLY-VARIABLE DRIVE MECHANISM Filed Sept. 1, 1951 2 Sheets-Sheet 1 [I I6 20 2 I 2 IO 26 |h LL 1 s |l l2 ||Hl HULL l n Fig. 4

3nnentor MICHAEL F GA PB LL 8, 1953 M. F. CAMPBEL INTERMITTENTLY-VARIABLE DRIVE MECHANISM 2 Sheets-Sheet 2 Filed Sept. 1, 1951 Fig. 6

3nventor MICHAEL F. CAMPBELL 3 Patented Dec. 8, l953 INTERMITTENTLY-VARIABLE DRIVE MECHANISM Michael F. Campbell, Sterling, 0010.

Application September 1, 1951, Serial No. 244,820

1 Claim. 1

This invention is concerned with means in driven association with a single prime mover or source of power whereby a plurality of separate, like elements may be simultaneously actuated at intermittently variable speeds, and has as an object to provide an arrangement of such means wherein the speed variations affecting the actuated elements are solely a matter of hazard and entirely unpredictable.

A further object of the invention is to provide improved means for simultaneously actuating a plurality of separate, like elements at intermittently-variable speeds and in a common direction from a single power source.

A further object of the invention is to provide an improved unitary assembly of elements constituting an intermittently-variable drive mechanism for the simultaneous and non-synchronous actuation of a plurality of separate, like elements,

"which mechanism is compact, simple of construction and operation, positive and emcient in use, susceptible of ready adjustment for wide variation of the specific speed diiierentials deriving therefrom, and adaptable to operative association with a variety of specific installations and a1- rangements of elements to be actuated thereby. With the foregoing and other objects in View, my invention consists in the construction, arrangement, and combination of elements as hereiafter set forth, pointed out in my claim, and illustrated. by the accompanying drawings, in

which- Figure 1 is a plan View of a typical embodiment of the invention as applied to the simultaneous actuation of four separate, like elements at unpredictably and intermittently variable speeds. Figure 2 is a section longitudinally of the arrangement according to Figure l, on an enlarged scale and with. certain portions broken away to conserve space and to disclose otherwise concealed construction, taken substantially on the indicated line 2-2 of Figure 1. Figure 3 is a fragmentary, detail elevation, on a further enlarged scale, of

the rearward end of the typical unit assembly H shown in Figure 2. Figure l is a fragmentary, de-

The improved drive mechanism illustrated by the drawings and hereinafter described is primarily designed for operative association with a plurality of identical toy elements, such as horses, dogs, automobiles, and the like, which are suitably arranged on and for independent travel along or about a board or field simulating a race course, so that the actuation of said elements derivin from the improved mechanism is productive of a variation in the relative speeds of the actuated elements in a manner closely simulating a race or speed contest. Means analogous as to result are common and well known, but the particular distinctive characteristic of the instant invention is found in a structural arrangement whereby speed acceleration imparted to a given actuated element is intermittent and variable in a manner which is entirely a matter of unpredictable hazard, and hence the relative progress of the actuated elements may not be determined in advance through any evaluation of the mechanical relationships employed in the mechanism or through any computations predicated upon known mathematical principles.

In the illustrated embodiment of the invention an arrangement effective for the simultaneous actuation of four separate, like elements along parallel courses in simulation of a race therebetween is shown as mounted and assembled upon a rigid, skeleton frame Id, of any appropriate specific construction, definitive of an elongated, rectangular field or course adapted to be horizon tally disposed, as by means of frame legs engage aisle with and to upstand from a suitable supporting plane. Fixed in spaced parallelism to and longitudinally of the field or course defined by the frame It, conveniently by attachment to frame struts transverse to said'field or course, a plurality of track bars H is mounted, one such bar 'block l2, to which the toy figures employed may be removably and interchangeably clipped, and

for the slidable reception of one side of an endless cord loop l3 engaged with and to effect the translation of said block.

Each cord loop i3 is correspondingly longer than its associated track bar H and engages at the forward, or driving, end of the assembly with and about a grooved pulley i spacedly aligned with the adjacent end of the track bar in a freelyrotatable mounting on a shaft journaled on and transversely of the frame I!) and at the rearward end of the assembly each said cord loop engages with and about a similar grooved pulley l6 carried by and for rotation in the free end of a head blocl: l1 slidably associated with the corresponding end of the track bar, thereby to dis pose each of said loops 13 for travel between and about its supporting pulleys l4 and 56 with its up-' per reach or run slidably accommodated in the upper margin channel of the associated track bar H and for translation of its attached slide block l2 in and along said channel.

The shaft l5 operates through the pulleys M, as will hereinafter appear, to drivethe cords l3 along their respective trackbars and it is the function of each head block ll to normally ten-' sion its cord loop for effective driven reaction to rotation of the mounting pulley i l, for which purpose the inner end of the head block may be forked to embrace the adjacent end of its track bar ll, pins iii may bridge the head block fork through an elongated slot longitudinally intersecting the track bar, thereby to support said .ead block on and for extension and retraction relative to the track bar, and a retractile spring l8 may be engaged between appropriate points of the head block and track bar to urge the former into an extension outwardly from the latter and to a consequent tensioning of the cord loop engaged about the pulley it carried by the head block. The cord tensioning arrangement just described may be availed of to slacken the cord loop bights between the pulleys l4 and i6 and tnereby accommodate manual, or other, adjustment of the slide blocks l2 along their track bars, it being feasible to selectively and simultaneously retract all of the head blocks l! relative to their supporting track bars I i and thereby nullify the driving friction of the pulleys l4 relative to the cord loops 53 to an extent permitting the cords to slip freely about said pulleys. To effect such selective retraction of the head blocks ll, a rock shaft 25 is journaled in members of the frame ll] transversely of the frame rearward end beneath the corresponding ends of the track bars H and is equipped with a handle 2i whereby it may be oscillated in its mounting, ends of one of the pins l8 connecting each head block to its track bar being extended to project perpendicularly from and at each side of the associated head block, and fingers if being fixed in and projecting radially from the rock shaft 2% in position to engage behind such pin is end extensions when the handle 2! is rocked forwardly and thereby shift the head blocks in their slide mountings and against the pressure of the tensioning springs l 9.

As above noted, the pulleys l l are freely rotatable on their mounting shaft ill but they are held in alignment with their respective track bars H and against displacement axially along said shaft by suitable means, such as. pins or collars 23, and rotation of said shaft ill in a direction to advance the slide blocks :2 from the rearward end to the forward ends of the track bars I! is positively transmitted to eifect corresponding rotation of all of the pulleys i l through a springloaded detent 24 carried by each pulley E4 in coaction with a ratchet gear 25 fixed to the shaft l5, thus to assure simultaneous and synchronous rotation of the shaft is and pulleys M in an operative drive direction while accommodating overrun, or higher speed rotation, of said pulleys 14 on and relative to the shaft l5.

A shaft 26 is journaled for rotation on the frame I0 in spaced parallelism with the shaft l5 and corresponding ends of said shafts l5 and 2G exterior to the frame mount like pulleys 2'! in 00- planar relation with the drive pulley 28 of a gear reducer, or transmission, 29 powered by an electric motor 39, so that a belt 3| operatively connecting the two pulleys 27 with the drive pulley 28 is effective to simultaneously and synchronously rotate said shafts I5 and 26 in the same direction and at a slow speed determined by the unit 29 whenever the motor 38 is energized, thus to drive the pulleys l4 and uniformly advance the slide blocks I2 along their track bars. Ihe actuation thus applied to the separate slide blocks and associated toy elements of the assembly through the arrangement of means so far described is simultaneous and uniform, and it is the function of the means and connections hereinafter set forth to intermittently vary the uniform actuation of the separate block and toy elements in a manner which will preclude advance determination of the relative progress thereof.

For the purpose just set forth, each of the pulleys I4 is furnished with a concentric, fixedlyassociated, chain sprocket 32, all of which are alike, and an annularly-grooved drum 33, of a diameter exceeding that of the sprocket 32, is fixed to the shaft 26 for operative association with each said sprocket 32 and hence with its annular groove coplanar with the coacting sprocket. A ladder chain 34, or the equivalent, is engaged as an endless loop with each sprocket 32 and loosely about the aligned drum 33, engaging within the annular groove of the latter, so that as the shafts l5 and 26 are synchronously and simultaneously driven, as above set forth, the chain 34 is steadily and uniformly advanced by each sprocket 32 and slips relative to the periphery of the associated drum 33. However, the face of the drum 33 annular groove engaged by the chain 34 is intersected by a succession of apertures 35 of a size to accommodate the stems of headed pins 38 loosely charged in suitable quantity within the hollow drum interior and hence effective, at hazard as to number and occasion, to traverse and protrude through one or another of the apertures 35 as a tooth or teeth temporarily intercoupling the drum 33 and chain 34 and applying power rotation of said drum, through the relatively greater drum diameter, to increase the speed of rotation of the associated sprocket 32 and the pulley l4 fixed thereto, thus imparting a spurt of speed to the slide block and toy element under advance through the agency of the cord loop l3 driven by said pulley i l. The pins 36 engaging through the holes 35 with links of the chain 34 will maintain a driving connection between a drum 33 and its associated chain only so long as the chain continues to conform to the contour of the drum and maintains a pressure against the projecting pin stem sufficient to hold the latter against the influence of gravity tending to return the pin to the lower portion of the drum interior as the drum is rotated to carry the projecting pin upwardly into position for gravity release from its engagement through the hole 35, it being obvious that as the chain becomes tangent to the drum its links move outwardly relative to the projecting pin stem and soon release the pin to fall back within the drum interior. Each drum normally contains the same number of identical pins 36, though the number of such identical pins in a given drum may be varied as desired. The probability of a pin engaging to interconnect a given drum 33 with its chain 34 varies somewhat according to the number of identical pins 36 within the drum. The specific shape of the pins 36, the size and number of the holes 35, and the size relationship between the holes 35 and pin stems may all be varied to increase or decrease the probability of driving engagement between a drum 33 and its chain 3%, but actual use of the apparatus has demonstrated that with the same number of identical pins 36 in each of a plurality of like drums 33 it is entirely a matter of chance and unpredictable hazard as to how continuously, with what frequency, and in what order the pins 36 will adjust themselves to establish driving connection between their respective drums and associated chains.

In practical operation, the apparatus functions when the motor 30 is energized to continuously, simultaneously, and uniformly advance the slide blocks l2 and associated toy elements to which the cords l3 are attached along the track bars I l, and to intermittently accelerate the advance of certain of said slide blocks and toy elements as driving connection is established by the pins 36 between a drum 33 and chain 34 associated with the corresponding sprocket 32 and pulley 14. Through relatively simple and obvious modifications, the apparatus may conveniently be adapted for intermittently-variable actuation of elements continuously through closed circuits or orbits,

the specific form and arrangement of the actuatable elements being, per se, no part of the I claim as my invention: In an intennittently-variable drive mechanism having a powered shaft. like drive members spaced apart along and independently rotatable on said shaft, and ratchet and detent means similarly interengaging said drive members and shaft for simultaneous, synchronous rotation in one direction, means directly eifective in reaction to shaft drive to intermittently and unprediotably accelerate the rotation of individual drive members on and about their mounting shaft, said latter means comprising a second shaft spacedly paralleling and in synchronously-driven relation with said first shaft, a chain sprocket concentrically and fixedly associated with each said shaftmounted drive member, a drum of greater diameter than such sprocket fixed to and for rotation with said second shaft in operative alignment with each said sprocket, an annular groove peripherally of the drum, an endless chain engaging each sprocket and embracing the associated drum in sliding accommodation within the groove thereof, holes intersecting the floor of the drum groove, and a plurality of headed pins loosely within the drum for haphazard protrusion of their stems through said holes and into temporary latching engagement with the chain links.

MICHAEL F. CAMPBELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 786,485 Clanner Apr. 4, 1905 989,732 Townsend Apr. 18, 1911 2,141,777 Watling Dec. 27, 1938 FOREIGN PATENTS Number Country Date 137,771 Great Britain Jan. 22, 1920 543,580 France June 7, 1922 

